Valve-gear for steam-engines



.fModel W. JOHNSON. I ValveGear for Steam Engines. Nd. 241,495.

Patented. May 1?, i ssr.

' F LME rim N. PETERS, Phoio-Lithographr, Washingiun. DC,

UNITED "STATES PATENT OFFICE.

W'ILLIA-M JOHNSON, OF LAMBERTVILLE, NEW JERSEY.

VALVE- GEA'R FOR STEAM -ENG'I"NES.

SIE'ECIFICAJJJION forming part of Letters 'Patent No. 241,495; dated May 17,1881.

Application filed March 18,1881. (ModcL) To all whom it may concern:

Be it known that I, WILLIAMJoHNsoN a citizen of the United States, residing. at Lambertville,"in the county ofrHunterdon and State of New Jersey, have invented certain new and useful Improvements inValve-Gear for-Steam- Engines; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable others skilled in the art to which it appertains to make. and use the same,reference being had to the accompanying drawings, and to the letters or figures of reference marked thereon, which form a part of this specification.

My invention consists in a governor'mechanism for controlling the cut-off valves of engines, whereby the point of cut off isautomatt. cally determined by the speed of the engine, the construction being more fully hereinafter described.

In the accompanying drawings, Figures 1,2, and 5 represent end elevations of myimproved cut-ofi governor, Figs. 2 and 5 showing modifications. Fig. 3 is a sectional view taken on line so aof Fig. 2 of the drawings. Figs. 4

- and 6 represent a fixed and an adjustable eeend of which is attached to disk B'by pivot a,

while the other end has a cylindrical flange, a, surrounding shaft A.

D is an eccentric ring, fitted to turn freely upon the cylindrical flange of O.

E E are reactionary levers, supported upon stud-pins e c fixed in disk B, one end of each of said levers being connected to the pendulous lever 0 upon one side of their center of motion, while the opposite ends are connected to the eccentric ring D upon the other side by means of the connecting-rods b b.

F F are weights connected to the reactionary levers by lever-arms H H.

G G are springs attached to disk B and levers E E. l

a preponderating force.

The operation isas follows: Motion. is communicated to the engine-shaft by the. action of the steam against the pistonin the usual manner. The centrifugal force of the Weights and tension of the springs are adj usted= to an equilibrium for the desired-speed. Any change of speed will cause a movement of: the weighted arms,-the direction of which will depend upon whether the chan ge is an increase or a decrease of the speed of the engine, and whether the weights or the springs by reasonthereof have multaneous movementwill begiven to thependulous lever and eccentric ring, which form a compound eccentric,lthe pendulouslever being moved across while the eccentric ring is turned around the axis of the shaft, and as the cut-off valve is connected to the eccentric by the usual arrangement of straps and rods, it will be seen that the automatic movement of the weighted arms will control the movement of the cut-off valve, and that the point of cut of will thus be automatically determined by the speed of the engine.

In the modification shown in Fig. 2 the connecting bar or casting K is moved across the axis of the shaft by the weighted lever-arms. The eccentric ring D turns freely upon the cylindrical flange aof K, and has a pin, 01, which projects from one side into a slot in the fixed eccentric L, as shown in Fig. 4. The move ment of the connecting bar orcastin g will cause the eccentric ring to turn thereon by reason of the pin and slot, and the combined movement will change the throw and lead of the eccentric, by which the speed of the engine is automatically controlled and governed, as before described. In that of Fig. 5 the pendulous lever is moved across the axis of the shaft by the weighted lever-arms, and the eccentric ring is a part of or is firmly fixed upon the cylindrical portion of the pendulous lever, and moves with but not upon the pendulous lever. The

movement of the pendulous lever across the axis of the shaft determines the position of the eccentric, stroke of valve, and consequent point of cut off, as will be clearly understood from the drawings and foregoing description.

The movement of I am aware that an eccentric has been revolved or turned'within an eccentric ring by means of weights and springs for the automatic adjustment of en gine-valves, the said eccentric ring being held from turning with the eccentric by means of a pin in the eccentric riu g, which slides in aslot in the fixed eccentric or disk, and by which the eccentric ring is driven or made to revolve with the shaft. I am also aware that a pendulous lever having a fixed eccentric has been moved across the axis of the driving-shaft by means of weighted levers and springs revolving therewith, said movement of the pend ulousleverbein g effected by turning a collar or sleeve upon the shaft; but with neither of these arrangements does the construction here shown conflict. I therefore do not claim the same; but

What I do claim as myinvention, and wish to secure by Letters Patent, is

1. A eut-ofi' mechanism consisting of a flanged plate and an eccentric ring, both adjusted across and around the axis of the shaft by means of a governor, as and for the purpose set forth.

2. In a governor cut-off, an adjustable compound eccentric adapted to be moved across and around the axis of its drivingshaft by means substantially as described, whereby as the work increases or decreases the speed of the en gine is automatically controlled.

3. In a cut-off mechanism, weighted levers revolving with the driving-shaft, incombination with a compound eccentric consisting of a concentric ring and an eccentric ring, which are moved across and around the axis of the driving-shaft by means substantially as de' scribed, and for the purpose set forth.

4. In a governor cut-off a pendulous lever one end of which is adapted to be moved across the axis of the driving-shaft by weighted levers attached to a disk revolving in unison with the pendulous lever, combined with an eccentric ring, the eccentricity of said ring, combined with the eccentricity caused by the pendulous lever moving across the shaft, serving to control and regulate the movements of i the engine.

5. In a governor cut-off, a pendulous lever one end of which is adapted to be moved across the axis of the driving-shaft by weighted and pivoted ley'ers, combined with an eccentric ring which moves with and around a flange placed upon the pendulous lever, and is also connected with the above pivotedlevers, as and for the purpose set forth.

6. In a governor cut-off, the revolving disk or wheel provided with the reactionary bellcrank lover or levers, and adapted by connecting-rods to convey a double movement to the compound eccentric, as and for the purpose set forth.

In testimony whereof I have affixed my signature in presence of two witnesses.-

' WM. JOHNSON.

Witnesses:

W. F. HERR, ALFRED B. HOLCOMBE. 

